Chinese Foreign Minister Wang Yi has begun a visit to Japan described as a major step forward in improving frosty relations, as Tokyo tries to stay involved in a flurry of international diplomacy over North Korea.

Wang met his Japanese counterpart Taro Kono for talks that were expected to touch on economic relations, territorial disputes in the East China Sea and ways to push Pyongyang to give up its nuclear weapons.

“I would like to regard [Wang’s visit] as a major step forward in our efforts towards improving Japan-China relations,” Kono told Wang at the start of their meeting at the Iikura Guest House.

Wang said his visit was China’s answer to “positive” messages and policies by Japan.

“We are also faced with some complex and sensitive elements,” said Wang, a former ambassador to Tokyo.

“But together with Japan’s efforts ... we would like to bring China-Japan relations back on a path of sustainable and normal development.”

The world’s second and third-largest economies have a fraught relationship, complicated by long-standing disputes over maritime claims and Japan’s wartime legacy.

But Tokyo is eager to get the relationship back on a firmer footing, especially as it fears being shut out of negotiations on North Korea’s nuclear programme in which Beijing is likely to be a major player.

China showed its significant influence over its reclusive ally when Chinese President Xi Jinping hosted North Korean leader Kim Jong-un and his wife in Beijing last month.

Japan hopes to expand its exchanges with China to stay involved as international efforts to engage Pyongyang intensify. South Korean President Moon Jae-in and US President Donald Trump are preparing for separate direct talks with Kim.

Kono, who visited Beijing in January, stressed that Japan and China shared the same goal on North Korea.

“I hope Japan and China will further cooperate towards our shared goal of the irreversible, verifiable and complete denuclearisation of North Korea,” he said.

Japanese Prime Minister Shinzo Abe, who is due to meet Trump in Florida on Tuesday to discuss North Korea, will meet Wang on Monday.

The visit is also seen as paving the way for a possible trilateral summit next month involving Abe, Chinese Premier Li Keqiang and South Korea’s Moon.

Tokyo hopes such a meeting will lead to a long-awaited exchange of state visits between Abe and Xi.

The time is ripe for the two nations to improve relations to mark the 40th anniversary of their 1978 Treaty of Peace and Friendship, both ministers said.

“I would like us to build peaceful and friendly relations befitting the name of the treaty,” Kono said, adding that the two nations are “partners in cooperation” and share an understanding that they should not threaten each other.

Wang, who will be in Tokyo until Tuesday, will also take part in the fourth China-Japan High-level Economic Dialogue.